code: def testFileReadBadMode(self):
      file_path = os.path.join(self._base_dir, "temp_file")
      gfile.GFile(file_path, mode="w").write("testing")
      self.assertTrue(gfile.exists(file_path))
      with self.assertRaises(errors.PermissionDeniedError):
          gfile.GFile(file_path, mode="w").read()
  
imports: import os.path
  from tensorboard import test
  from tensorboard.compat.tensorflow_stub import compat, errors
  from tensorboard.compat.tensorflow_stub.io import gfile
label_desc: Use image node_id 10 for calling the FileIoTest obj's underlying member method code with example usage: obj.testFileReadBadMode() without return types